Throttle valve actuating apparatus



Jam. 7, 1964 3,116,906

L- F. CALLAHAN THROTTLE VALVE ACTUATING APPARATUS Filed July 21, 51.961

' FIGQ 50 Y 4/ FIG.IO

INVENTOR.

LAWRENCE F CALLAHAN ATTORNEY United States Patent G THROTTLE VALVEACTUATING APPARATUS Lawrence F. Callahan, Kenosha, Wis., assignor toAmerican Motors Corporation, Kenosha, Wis., a corporation of MarylandFiled July 21, 1961, Ser. No. 125,737 8 Claims. (Cl. 251-64) Theinvention relates to a throttle valve actuating device for an internalcombustion engine and has particular reference to a mechanism formomentarily retarding valve closing throughout the final few degrees ofvalve operating range.

The principal object of the invention is to provide mechanical means formomentarily retarding final valve closing.

Another object is to provide such a mechanism for the purpose ofreducing the possibility of killing the engine by too rapid valveclosing.

A further specific object of the invention is to provide mechanism foreffecting limited frictional resistance to valve closing throughout thefinal 4 or degrees of the valve closing range.

Other objects and advantages of the invention will be apparent from theensuing specification and appended drawing in which:

FIG. 1 is a side elevational view of a typical throttle valve actuatingapparatus employing the inventive subject matter.

FIG. 2 is a fragmentary end view taken generally on the line 22 of PEG.1 with parts broken in section.

FIG. 3 is a fragmentary view taken on the line 33 of FIG. 2 with partsbroken in section.

FIG. 4 is a fragmentary view taken on the line 44 of FIG. 2, but withthe throttle valve rotated to closed position.

FIG. 5 is a detail plan view of one component.

FIG. 6 is a detail plan view of another component.

FIG. 7 is a fragmentary sectional view similar to FIG. 3 but showing amodified form of the invention.

FIG. 8 is a detail plan view of a component of the device shown in FIG.7.

FIG. 9 is a sectional detail view taken generally on the line 99 of'FIG. 1.

FIG. 10 is a fragmentary sectional detail view of the end portion of thethrottle valve shaft.

Referring to FIG. 1, I have shown a typical throttle valve actuatingassembly as utilized in an automotive vehicle. A carburetor A is mountedon engine B and the throttle valve C is actuated by the rotation ofaccelerator shaft D. A foot pedal E is initially actuated for effectingrotation of the accelerator shaft.

The accelerator pedal E is mounted on the toeboard 10 and its upper endis connected to actuating rod 11 which projects through a suitableopening 12 in the toeboard. A bracket 13 has its base portion anchoredto the toeboard as by means of screws 14. Crank 15 is carried by thebracket and one crank arm 16 is pivotally connected at 17 to the innerend of the actuating rod 11 and crank arm 18 is pivotally connected at19 to the lower end of link 20. The upper end of link 20" is pivotallyconnected to the bracket 22 which is anchored, as by welding, to theaccelerator shaft D.

A bracket 23 is anchored at its lower end to the side face of bracket 13and carries a bearing 24 at its upper end. The bearing rotativelyaccommodates the outer end 25 of the accelerator shaft.

A tension spring 27 has one end 28 anchored to the bracket 13 and itsother end 29 anchored to the pivot pin 17 which interconnects the crankarm 16 and actuating rod 11.

3 ,116,906 Patented Jan. 7, 1964 All of the foregoing throttle valveactuating mechanism forms the subject matter of a co-pending patentapplication, Serial No. 122,492, filed on July 7, 1961.

The throttle valve C is mounted within the carburetor housing 31 on thethrottle valve shaft 32. The valve shaft projects exteriorly of thecarburetor housing and has a bracket '33 anchored to the outer endthereof. The accelerator shaft D is bent at 34 and at 35 to provide thetransverse end portion 36 which extends through the aligned openings 38and 39 in bracket 33. Thus, rotation of the accelerator shaft istransmitted to the valve shaft 32 via rotation of bracket 3-3.

Referring to FIGS. 2 and 10, it will be noted that the outer end of thevalve shaft has diametrically opposed flats 40 and 41 which lock thebracket 33 to the shaft so that it effects rotation of said shaft. Asecond set of diametrically opposed flats 42 and 43 serve to accommodatethe spring Washer 45 and cam Washer 46. At the ends of the flats 4t) and41 radially extending shoulders 47 and 48 are formed, against which theunderside of bracket 33 bottoms.w The head portion 50 at the outer endof the valve shaft anchors the bracket against axial movement relativeto said shaft.

Referring to FIGS. 5 and 6, the spring washer 45 is provided with acentral opening 52 with flats 53 and 54 which coact with the shaft flats42 and 43. The cam washer 46 likewise has a central opening 55 withflats 56 and 57 which coact with shaft flats 42 and 43. The cam washerhas a cam surface identified generally with the numeral 58 formedtherein, preferably as by means of a punch press operation. At the endsof the shaft flats 42 and 43 shoulders 60 and 61 are formed and when theunderside 62 of the cam washer engages said shoulders under theinfluence of spring washer 45, the apex portion 63 of the cam will beslightly spaced from the end face 64 of the carburetor housing 31. Aplug 65 may be pressed into the end wall of the carburetor housing andhas a semi-spherical end surface 66 projecting outwardly therefrom. Whenthe underside 62 of the cam washer is in contact with shaft shoulders 60and 61, then there is preferably a slight clearance between the end ofthe nose portion 66 and the underside of the cam washer.

When the throttle valve moves to within 4 or 5 degrees of fully closedposition, the inital portion 68 of the cam engages the nose of the plug65 and when the throttle valve reaches fully closed position, the apexportion 63 of the cam will be resting on the plug nose as viewed in FIG.4 and the spring washer 45 will be substantially fully compressedbetween the underside. 70 of the bracket 33 and the upper side 71 of thecam washer as shown in FIG. 4.

In the modified form of the invention as shown in FIGS. 7 and 8, thespring washer and cam means are incorporated in one component. Thecomponent is provided with a central opening having flats 81 and 82which coact with the shaft flats 83 (only one of which is shown in FIG.7). The washer forms a nearly complete circle; however, the gap 84between the ends 85 and 86 make it possible to utilize the cam 87 as thespring (comparable to the spring washer 45). When the underside 88 ofthe washer is in contact with the shaft.

shoulders provided at the ends of the flats 83, there will preferably bea slight clearance between the cam and the end shoulder 64a of thecarburetor housing and between the underside of the washer and the end66a of the plug 65a.

Operation In the operation of the throttle valve actuating apparatus,the accelerator pedal is depressed to effect opening of the throttlevalve. Downward movement of such pedal causes rod 11 to swing the crankarm 16 and 18 clockwise about the horizontal axis 90. Crank arm 18 pullslink 2% and bracket 22 downward to effect rotation of accelerator shaftD in a counter-clockwise direction viewing FIG. 9. Rotation of suchshaft to fully open valve position will rotate the valve shaft 32 andbracket 33 to the position as indicated in FIG. 2. When the footpressure on the accelerator pedal is released, the return spring 27takes over and automatically returns the valve to fully closed posiiton.In fully closed position, the apex of the cam will overlie the nose ofthe plug 65 as shown in FIG. 4.

Viewing FIG. 2, the closing of the valve will cause ro tation of thebracket 33 clockwise to a position approximately 80 degrees beyond thatshown in FIG. 2. The range of movement of the accelerator shaft fromfully opened to fully closed position is indicated by the dimension X.Open position is indicated by the line 95 and closed position isindicated by the line 96. The final 4 or 5 degrees of valve closing isindicated by the dimension Y and it is during this range of movement ofthe valve shaft that the cam commences riding up on nose 66 against theresistance offered by the spring washer 45 until the washer issubstantially flattened as indicated in FIG. 4. The resistanceoccasioned by the spring washer is calibrated in conjunction with thetension exerted by spring 27 so that the final 4 or 5 degrees of valveclosing results in a slowing down of the closing movement of the valveshaft thereby preventing an abrupt valve closing condition. Thus, thelikelihood of the engine dying as a result of abrupt valve closing islessened.

Viewing FIG. 3, it will be noted that the clearance shown, for example,between the periphery of the spring washer 45 and the underside 70 ofbracket 33 is greatly exaggerated for purposes of clarity in detail ofthe drawing; however, in practice the clearance between the variouscomponents need only be such as to assure that little or no frictionaldrag occurs during valve opening and closing throughout the range ofoperation other than the final few degrees of closing. Thus, in FIG. 3the clearance shown between washer surface 62 and nose 65 and theclearance shown between the cam apex 63 and carburetor housing face 64are also exaggerated.

Clearance exaggeration also exists in FIG. 7 between washer face 88 andnose 66a and between the cam surface and carburetor housing wall 64a.

I claim:

1. A carburetor throttle valve control mechanism comprising: a throttlevalve; a shaft for rotatively actuating the valve between closed andopen positions; a carburetor housing rotatively supporting the shaft,said shaft projecting beyond an end wall of the housing; means foractuating the rotation of the shaft to open the valve; spring means foreffecting rotation of the shaft automatically to close the valve andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: a cam surface rotatable with the shaft; an abutment onthe carburetor housing situated in the path of rotation of the camsurface and resilient means on the shaft and being energized when thecam surface rides over the abutment.

2. A carburetor throttle valve control mechanism comprising: acarburetor housing; a throttle valve within the housing; a valve shaftcarrying the valve and being rotatably supported by the housing andhaving an end projecting through one wall of the housing; means foreffecting rotation of the shaft in valve opening direction to open thevalve; spring means for automatically rotating the shaft in valveclosing direction upon inactivation of the valve opening means; andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: a cam surface rotatable With the shaft; cam receivingmeans non-rotatable with reference to the shaft and situated in the pathof rotation of the cam surface and resilient means on the shaft forresisting movement of the cam surface over the cam receiving means.

3. A carburetor throttle valve control mechanism comprising: acarburetor housing; a throttle valve within the housing; a valve shaftcarrying the valve and being rotatably supported by the housing andhaving an end projecting through one wall of the housing; means foreffecting rotation of the shaft in valve opening direction to open thevalve; spring means for automatically rotating the shaft in valveclosing direction upon inactivation of the valve opening means; andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: a washer non-rotatably mounted on the shaft andaxially movable relative thereto; a cam surface on the washer; anabutment on the carburetor housing wall and situated in the path ofrotation of the cam surface; resilient means on the shaft and normallyurging the Washer in an axial direction along the shaft toward theabutment, said cam surface riding over the abutment and the resilientmeans serving to resist the riding of the cam surface over the abutment.

4. Apparatus as set forth in claim 3 wherein the torque load imposed onthe shaft by the spring means in rotating the shaft in valve ciosingdirection exceeds the resistance to such torque load occasioned by theresilient means as the cam surface rides over the abutment.

5. Apparatus as set forth in claim 3 wherein the shaft has a shoulderfor limiting the axial movement of the Washer toward the abutment.

6. A carburetor throttle Valve control mechanism comprising: acarburetor housing; a throttle valve within the housing; a valve shaftcarrying the valve and being rotatably supported by the housing andhaving an end projecting through one wall of the housing; means foreffecting rotation of the shaft in valve opening direction to open thevalve; spring means for automatically rotating the shaft in valveclosing direction upon inactivation of the valve opening means; andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: a washer non-rotatahly mounted on the shaft andaxially movable relative thereto; a resilient cam surface on the washer;an abutment on the carburetor housing wall and situated in the path ofrotation of the cam surface; said resilient cam surface riding over theabutment and simultaneously serving to resist the rotative torqueimparted to the shaft by the spring means.

7. A carburetor throttle valve control mechanism comprising: a throttlevalve; a shaft for rotatively actuating the vaive between closed andopen positions; a carburetor housing rotatively supporting the shaft,said shaft projecting beyond an end wall of the housing; means foractuating the rotation of the shaft to open the valve; spring means foreffecting rotation of the shaft automatically to close the valve andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: cam means and resilient means associated with theshaft and with the carburetor housing; whereby rotation of the shaft invalve closing direction throughout the final few degrees of rotativemovement causes energizing of the resilient means to effect suchresistance to valve closing.

8. A carburetor throttle valve control mechanism comprising: acarburetor housing; a throttle valve within the housing; a valve shaftcarrying the valve and being rotatably supported by the housing andhaving an end projecting through one wall of the housing; means foreffecting rotation of the shaft in valve opening direction to open thevalve; spring means for automatically rotating the shaft in valveclosing direction upon inactivation of the valve opening means; andmeans for resisting the valve closing effort of the spring meansimmediately prior to such valve reaching fully closed position, saidmeans comprising: a cam surface mounted on the shaft for axial movementrelative thereto and being rotatable with the shaft; cam receiving meansnon-rotatable with reference to the shaft and situated in the path ofrotation of the cam surface and resilient means on the shaft and beingenergized when the cam surface moves over the cam receiving means,thereby resisting the movement of the cam surface over the cam receivingmeans.

References Cited in the file of this patent UNITED STATES PATENTS

1. A CARBURETOR THROTTLE VALVE CONTROL MECHANISM COMPRISING: A THROTTLEVALVE; A SHAFT FOR ROTATIVELY ACTUATING THE VALVE BETWEEN CLOSED ANDOPEN POSITIONS; A CARBURETOR HOUSING ROTATIVELY SUPPORTING THE SHAFT,SAID SHAFT PROJECTING BEYOND AN END WALL OF THE HOUSING; MEANS FORACTUATING THE ROTATION OF THE SHAFT TO OPEN THE VALVE; SPRING MEANS FOREFFECTING ROTATION OF THE SHAFT AUTOMATICALLY TO CLOSE THE VALVE ANDMEANS FOR RESISTING THE VALVE CLOSING EFFORT OF THE SPRING MEANSIMMEDIATELY PRIOR TO SUCH VALVE REACHING FULLY CLOSED POSITION, SAIDMEANS COMPRISING: A CAM SURFACE ROTATABLE WITH THE SHAFT; AN ABUTMENT ONTHE CARBURETOR HOUSING SITUATED IN THE PATH OF ROTATION OF THE CAMSURFACE AND RESILIENT MEANS ON THE SHAFT AND BEING ENERGIZED WHEN THECAM SURFACE RIDES OVER THE ABUTMENT.